The most valued tanzanites (zoisites) are typically vivid, violet-blue crystals with greenish or orangey stones being rare. Heat treatment is applied to enforce the violet color component.

Tanzanite 2.34 cts.Published under permission: Miguel Angel Lopez

The figures are based on Gemval's aggregated valuation statistics for the retail market. Irrelevant, controversial or repeat data are excluded from our analysis wherever possible. The figures are updated monthly.